“TV transmitter emits radio waves that under normal conditions cannot be detected by a receiving antenna due to Earth’s curvature. However, if a meteor passes more or less at half the receiver-transmitter distance, its ionized trail is able to reflect transmitter waves to the receiving antenna and produces radio waves. The antenna is connected by a coaxial cable to a radio receiver, which finally redirects the signal to a computer for automated meteor detection and counting”. (Victoria)
The telescope has the following main characteristics:
- Synthesized tuning. The telescope should be able to be tuned and pointed to the astronomical object during calibration.
- The telescope should provide the options for continuous wave and single sideband demodulation of the radio signals.
- It also has VHF coverage in the frequency range 30 MHz to 150 MHz
- It should also have an audio line output for connecting to a computer which has the software
It is essential that during the observations the following steps are followed: (Nasa)
- Antenna calibration. First, we connect to the PARTNeR Remote Control Center though a remote desktop. Then, calibrate the instrument from db to antenna temperature which is usually the measured flux.
- Pointing calibration. This is checking the pointing if it is done to the objects that are close to the targets whose location is defined and knowned.The meteors distance is 1150km, 2300 will be the upper limit or the baseline. One should ensure that the antenna is points accurately to the source to be observed, the meteors. The measurement movement should be done in vertical and horizontal direction to the source. Ordinarily bad pointing results in an offset
- Target observation and measurement of the radiation. Observe the transmitter as the antenna points on the target, and halt it to let the Earth rotation do the work: The source will be moving before the antenna, thus allowing us to measure its flux.
- Tipping curve. “In their way to the antenna, the radio waves have to get through the atmosphere. The thickness of the atmosphere depends on the source elevation. The tipping curve, or antenna temperature curve, is derived by scanning the sky in a trajectory that follows the elevation along the meridian, from the horizon to the zenith”. (Nasa)
Ordinarily, the Radio telescope will record the sum of the meteors reflections that are detected in a specific time interval. This will be done by measuring the different power values and measurements which are converted into temperature values (K).It should be done in several days while the system remains intact and not changed. There is need to measure the two measurements in spectrum that is the thermal radiation (temperature) and Synchrotron radiation. The two measurements can give the Orion of radiation.
The signals will be observed, using internet connection. This will be done by internet connected software such as Meteor V8.0 (http://radio.meteor.free.fr/fr/en/ ) which will detect and count the meteor signals. (David) The signals will be detected as light and not sound. When the “STOP” button in the antenna control interface is pressed and then “TIPPING” button, the antenna moves to low elevation position of -40º and then start to count to 50 K and about 2400 km.The result has shown that the source is very intense, because peak is higher than baseline.
The important thing I have learned today is that when measuring co-ordinates in the centre, the radio image will be two wave lengths with a hole in the middle. However what remains unclear is how bad pointing could result in an offset.
David. Radio Meteor Observing. 2013. 2015 <http://www.popastro.com/meteor/observingmeteors/radioobserving/index.php>.
Nasa. “Quick guide to astronomical observations.” Mc Grill Hall, 2013.
Victoria. Radio observations of meteors. 2015. 2015 <http://www.tng.iac.es/users/boschin/ms.html>.